Phosphorus Test

Abnormally high or low levels of phosphate in the body indicate several health conditions. Therefore, this test is useful in the diagnosis of many different conditions. It is generally recommended in individuals with:

• Suspected kidney disorder
• Suspected gastrointestinal disease, as the absorption of phosphate occurs in the gastrointestinal tract
• Fatigue and weakness
• Bone problems, as phosphorus is involved in maintaining healthy bones

No special preparations are needed before this test but the doctor may recommend stopping some medicines that could affect test results. Also, the individual should inform the doctor about any herbal or vitamin supplements that may be taking as these may interfere with the results. For the same reason, consumption of certain food items, like cheese, fish, beer, cola, chocolates and different types of beans should be avoided before the test.

Do not skip any medicines without consulting the doctor.

A blood sample is needed for this test, which is collected as follows:

• The site from which the sample is to be collected (usually the vein of an arm) is cleaned with an antiseptic solution.
• An elastic band called a tourniquet is tied around the arm, which helps to locate the vein easily
• The needle is then inserted into the vein in the arm or hand, and a blood sample is drawn and collected into a vial
• The tourniquet is removed and a dressing is applied at the injection site

The needle may cause some discomfort and pain during blood collection. A stinging and pricking sensation may be experienced after the test for some time.

Common risks associated with blood tests include bleeding, infection, hematoma (accumulation of blood under the skin), bruising and lightheadedness.

Phosphorus test results may vary based on age, sex, the current and previous health status of the individual and method used for the test. Consult a doctor for the correct and most appropriate interpretation of test results.

Normal results:

The normal values of phosphorus in a healthy individual vary with age. Normal phosphorus levels range between 2.8 to 4.5 mg/dL in adults and 4.0 to 7.0 mg/dL in children.

However, these values differ slightly among various laboratories.

Abnormal results: 

A higher-than-normal level of phosphate is called hyperphosphatemia, which could be caused by:

• Excessive vitamin D
• Hypoparathyroidism, i.e., insufficient production of parathyroid hormones from parathyroid glands
• A life-threatening condition called diabetic ketoacidosis seen in individuals with diabetes
• Kidney failure
• Excessive phosphate intake through diet
• Liver disease
• Consumption of phosphate-containing medicines like laxatives

A lower than normal level of phosphate is called hypophosphatemia, which can occur due to:

• Alcohol intake
• Low intake of phosphate-containing foods in diet
• Hypercalcaemia, i.e., increased calcium levels in body
• Lack of nutrition
• Primary hyperparathyroidism, i.e., abnormally high production of hormones by the parathyroid glands
• Lack of vitamin D resulting in diseases of the bones such as rickets in children and osteomalacia

Disclaimer: All results must be clinically correlated with the patient’s complaints to make a complete and accurate diagnosis. The above information is provided from a purely educational point of view and is in no way a substitute for medical advice by a qualified doctor.